Device for communications between a plurality of functional modules installed in a local unit and an ARINC 629 type external bus

Abstract

In order to have the functional modules of a local unit communicate with one another and with an external bus, the device embodying the invention comprises: at least one internal bus of the same type as the external bus per functional module, the latter being coupled to the internal busses so that each module is the sole transmitter on at least one of the internal busses and is a receiver on the other internal busses; an additional internal bus for each external bus of the same type as said internal busses, ensuring the dissemination to the functional modules of data transiting on the external bus; and a coupling module ensuring transfer towards the external bus of the data circulating on the internal busses and destined for another local unit connected to the external bus.

We claim: 
     
       1. A device for communications between a plurality of functional modules installed in a local unit and a multiplexed, multitransmitter, multireceiver external bus for communications with other local units, said device comprising: at least as many internal busses as there are functional modules susceptible of transmitting data to the other modules of said local unit and to said external bus, each internal bus being of the multiplexed, multitransmitter, multireceiver type, and complying with the time protocol and the format of the data transiting on said external bus, said functional modules being coupled to said internal busses so that each module susceptible of transmitting data is the sole transmitter on at least one of said internal busses and a receiver on the other internal busses;   an additional internal bus associated with the external bus, ensuring dissemination within said local unit of the data transiting on said external bus, this dissemination bus being of the same type as said internal busses and being connected to said external bus and to said functional modules; and   a coupling module designed to transfer, to said external bus, data circulating on said internal busses and destined for another local unit connected to said external bus.   
     
     
       2. The device as claimed in claim 1, wherein each functional module comprises a control unit connected to each of the internal busses, designed to sort all the data circulating on the internal busses so as to only receive data destined for the module and to transmit data to said module on the internal bus allocated to transmission. 
     
     
       3. The device as claimed in claim 2, wherein the control unit is connected to non-volatile memories containing the identification and description of the characteristics of the data to be received and transmitted, as well as the sequencing of the data to be transmitted, the control unit comprising a means for detecting, on the internal busses, the data to be received, and for transferring the latter into an exchange memory. 
     
     
       4. The device as claimed in claim 2, wherein the control unit comprises a means for listening in on the bus assigned to transmission, for comparing, while they are being transmitted, the data transmitted on the bus with the data read simultaneously on the bus, and for invalidating the data transmission in process and generating an error signal when the comparison reveals a variance. 
     
     
       5. The device as claimed in claim 1, wherein the coupling module comprises a means for recognizing which data circulating on the internal busses are to be transmitted to the external bus. 
     
     
       6. The device as claimed in claim 1, wherein the data circulating on the internal busses and on the external bus are broken down into periodic frames, and of which the characteristics are defined in the tables connected to the control unit. 
     
     
       7. The device as claimed in claim 2, wherein the control unit is integrated into an ASIC. 
     
     
       8. The device as claimed in claim 1, wherein the coupling module comprises a first control unit connected to the internal busses not connected to the external bus, a first exchange memory connected to said control unit, to a processor, to a second exchange memory, and to a second control unit similar to the first one and transferring data from said second exchange memory to the external bus. 
     
     
       9. The device as claimed in claim 1, wherein the coupling module has an internal bus on which it is the sole transmitter, enabling it to send service and maintenance data to the functional modules of the local unit, so as to indicate, to the functional modules, the data transfer faults on the external bus as well as any failures. 
     
     
       10. The device as claimed in claim 8, wherein the coupling module comprises a series interfacing circuit converting the analog signal conveying the data on the external bus into a logic signal applied to the internal dissemination bus, and vice versa to transfer data emitted by the second control unit to said external bus. 
     
     
       11. The device as claimed in claim 8, wherein the coupling module is connected to a second external bus of the same type as the first external bus, and connected to an internal bus via a second series interfacing circuit, the processor being connected to a third exchange memory and to said second external bus via a third control unit and the second series interfacing circuit.